Automatic tool changer

ABSTRACT

A tool changer is disclosed for automatically removing a working tool after having been used from the spindle of a machine tool such as a vertical milling machine, transferring the used working tool to a rack which stores a plurality of working tools, picking up from the rack another working tool for the next machining operation, transferring such new working tool to the spindle, and operatively mounting such new working tool on the spindle.

[ Mar. 27, 1973 United States Patent 91 Hague et al.

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[73] Assignee: Moog Inc.,East Aurora,N.Y.

[57] ABSTRACT A tool changer is disclosed for aut-omaticall [22] Filed:

y removing a working tool after having been used from the spindle of a machine tool such as a vertical milling machine, transferring the used working tool to a rack which Related U.S. Application Data [62] Dmslo n of May 1969 stores a plurality of working tools, picking up from the [52] U.S. rack another working tool for the next machining "90/11 D, 279]] B, 279/1 E, 279/1 F, 279/53, 279/89, 29/26 A, 90/ 11 A operation, transferring such new working tool to the [51] Int. Cl. 5/04 .90/11 A, 11 D; 279/l B, l E,

spindle, and operatively mounting such new working tool on the spindle.

[58] Field of Sea'rch.....

279/1 F, 1 P, 5.1, 5.3, 46, 89; 29/568, 26 A 5 Claims, 76 Drawing Figures [56] References Cited UNITED STATES PATENTS 1,652,857 12/1927 Greve....................................279/lP PATENTEDmzmvs 3,722,363

sum 01 [1F 18 T 6 l8 T l5 INVENTORS Robgrt Z. Hague Edwm F Hontmon Howard H. LCIUCks eorge J. Loos Matthew F. Morsicano Alfred J. Mostropole BY M/ "4441412.

ATTORNEYS PATENTFDHARZYIHH ,7 2,353

SHEET 02 0F 18 H 9 iNVENTORS 5 4 Robgrt Z. Hague /|5 Edwln F. Huntmon 8 Howard H. Lcucks L- George J. Loos Matthew F. Murslcuno 3 J\ Alfred J:. Mcstropole ATTORNEYS PATEf-HEUHARZYIUH SHEET [13 0F 18 gue INVENTORS H0 dwm F. Hunt Robert 2. E

mun Loucks Loos Howard George J. Matthew F. Morslccmo Alfred J. Mustropole BY z N [JAR/ZN 7&44

I ATTORNEYS PATENTEUHARZYIEB 3.722.363

SHEET sum 18 INVENTORS Robgrt Z. H0 e Edwln F. Huntmcn Howard H Loucks George J. Loos Mors|cuno J. Mostropole Matthew F Alfred /4 BY Z W ATTORNEYS PATENTEUNARE'HSIS 722,353

SHEET 08 0F 18 I72 m2 I92 INVENTORS Robgrt Z. Hague Edwin F. Hommun Howard H. Loucks George J. Loos Matthew F. Morsicono Alfred J. Mostropole ATTORNEVS PATEHTEUHAR 2 71975 SHEET lUUF 18 BYJ SHEET 12UF 18 INVENTORS Hague HHuntmun Robert Z.

Howard Loucks George J. Loos Matthew F. Morsicono Alfred J. Mostropole BY u/nivb4um M) ATTORNEYS PATENTEUMARZYISH SHEET lUUF 18 PATENTEUHARwm SHEET lSUF 18 INVENTORS ogue ntmon Howard H. Loucks George J, Loos Matthew F. Mursicuno Alfred J. Must/rZpole BY ,g,, y- ME! AN, W ATTORNEYS a ZF mm mm RE PATENTEDHARZY I973 SHEET 98253 346 so s2 I E I l x J 4Il T lNVENT ORS Robert Z. Hague Edwin- F. Hcmtmun Howard H. Loucks George J. Loos Matthew F. Mursicono Alfred J. Mustropole ATTORNEYS PATENTEUHARZYIBH 3,722,353

SHEET 17 DF 18 ARM SWINGS HAND EXTENDS GENEVA HAND E%*. Hews RISES ARM LOWERS GENEVA HAND RETRACTS 656x5 SPINDLE HOOK DISCONNECTS HAND EXTENDS ARM SWINGS ARM SWINGS 4 5 HAND RETRACTS HAND EXTENDS ARM LOWERS GENEVA ARM GENEVA MECHANISM RISES MECHANISM LOCKED LOCKED SPINDLE HOOK CONNECTS HAND EXTENDS ARM SWINGS TIME IN SECONDS O l 2 3 4 ARM AT RACK ARM AT SPINDLE EXTENDED swrrcu ON RETRACTEDKHAN)! 288 I OFF LOCKED sP1ND1 s sw|TcH {OFF UNLOCKED HOOK 289 ON DRUM UP 0 cm DowN EXTENDED swmzu ON RETRACTED; 29: {OFF LOCKED -SPINDLE {SWITCH {OFF mwcxso HOOK 292 ARM DRIVE MOTOR-SWITDH 290! ARM DRIVE morowswrmu 293{ O 50 I00 I50 200 250 300 350 DEGREES OF ROTATION ilNVENTORS Robgrt Z. Hague Edwln F. Hommon 171 55. Howard H. Loucks George J. Loos Matthew F. Mursicono Alfred J. Musiropole BY W 1 MTDRNEYR' BACKGROUND OF THE INVENTION While machine tools equipped with automatic working tool changers are known, they suffer from such disadvantages as being complicated, bulky, interfering with the work site for a machining operation, slow, cumbersome, or are incorporated as an integral part of the machine tool itself so that the complete machine too] must be purchased to acquire the automatic tool changer feature and hence the cost is high.

SUMMARY OF THE INVENTION The present invention relates to an improved tool changer for a machine tool having a spindle, which broadly comprises a tool rack having a plurality of stations for storing a plurality of working tools severally adapted for drive connection to the spindle, the rack being mounted for rotation about a fixed axis generally parallel to that of the spindle and radially spaced therefrom, a transfer arm mounted for pivotal move ment about an axis generally parallel to the rack and spindle axes between a first angular position adjacent said rack and a second angular position adjacent said spindle and also mounted for translational movement axially of such axes, and an extendable and retractable working tool grasper arranged on the transfer arm.

The present invention overcomes the disadvantages of the piror art tool changers by providing automatic tool changing apparatus that: is more simple in construction and less expensive; is capable of adjustment for smooth and rapid operation; provides dependable service and is not likely to get out of order or require repairs; is compact and unobstructive when mounted on the machine tool with which it is associated; is adapted for retrofitting on suitable existing machine tools such as a vertical milling machine which is a type of machine tool commonly found in machine shops; and involves no mechanical interconnection as opposed to only related intelligence control between that portion of the apparatus which releasably holds a working tool on the spindle of the machine tool and that portion of the apparatus which transfers used and replacement working tools between the spindle and a tool storage site.

One of the outstanding advantages of the inventive tool changer is that a rotary device controls the timing of the drive for various functions performed during a tool change.

Another important advantage of the inventive tool changer, contributing materially to its comparative simplicity and inexpensiveness, is that its cycle of operation is programmed so that one part of the cycle is perfonned by rotation of the aforementioned rotary device in one direction and another part of the cycle is performed by reversing the direction of rotation of such device, thereby reducing the amount of mechanism required.

Other advantages will be apparent from the details of the preferred embodiment of the invention illustrated in the accompanying drawings and hereinafter described.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a vertical spindle milling machine embodying the present invention, viewed from the front and slightly to the left thereof.

FIG. 2 is a reduced top plan view of the machine tool shown in FIG. 1.

FIG. 3 is a fragmentary enlarged vertical sectional view thereof taken on line 3-3, FIG. 2.

FIG. 4 is a fragmentary enlarged vertical central sectional view through the centrifugal device arranged on the lower end of the main drive :motor shaft shown in FIG. 3, illustrating an above-critical speed condition of the device.

FIG. 5 is a view similar to FIG. 4 illustrating a belowcritical speed condition of the device.

FIG. 6 is a horizontal sectional view thereof taken on line 6-6, FIG. 4.

FIG. 7 is a fragmentary enlarged horizontal sectional view of the power driven spindle brake assembly, taken generally on line 7-7, FIG. 3.

FIG. 8 is a fragmentary enlarged horizontal sectional view of the power driven shifter mechanism for the back gear assembly shown in FIG. 3, this view being taken on line 8-8 thereof.

FIG. 9 is a fragmentary vertical transverse sectional view thereof taken on line 99, FIG. 8.

FIG. 10 is a fragmentary enlarged vertical central sectional view of the machine spindle assembly, with a central portion being broken away, taken generally on line 10-10 of FIG. 3 and illustrated in a spindle-toolconnected condition.

FIG. I 1 is a view similar to FIG. 10 illustrating a spindle-tool-disconnected condition.

FIG. 12 is a horizontal sectional view of the spindle assembly taken on line 12-12, FIG. 10.

FIG. 13 is a horizontal sectional view thereof taken on line 13-13, FIG. 10.

FIG. 14 is a fragmentary vertical sectional view thereof taken on line 14-14, FIG. 12.

FIG. 15 is a horizontal sectional view thereof taken on line 15-15, FIG. 10.

FIG. 16 is an enlarged horizontal sectional view of the drawbar operating mechanism taken on a plane indicated by line 16-16, FIG. 1.

FIG. 17 is a fragmentary horizontal sectional view thereof on the same scale as FIG. 16 but taken on a lower plane indicated by line 17- 17, FIG. 1.

FIG. 18 is a similar fragmentary horizontal sectional view thereof but taken on a still lower plane indicated by line 18-18, FIG. 1. 7

FIG. 19 is another fragmentary horizontal sectional view thereof taken on yet another lower plane indicated by line 19-19, FIG. 1.

FIG. 20 is a fragmentary enlarged vertical sectional view of a spindle pawl member shown in FIG. 19, being taken on line 20-20 of that figure, and showing in elevation a glide button for supporting such member.

FIG. 21 is a fragmentary vertical sectional view of the drawbar operating mechanism, taken on line 21- 21 of FIG. 17, and illustrating the operative condition of the mechanism for turning the drawbar nut.

FIG. 22 is a view similar to FIG. 21 showing the drawbar nut turning mechanism in an inoperative condition. 

1. In a control mechanism including a tubular support member and a drawbar arranged therein and having one end extending therefrom, the improvement which comprises a threaded section on said one end, a nut arranged on said threaded section in a tightened thrusting engagement against the end of said support member, means cooperating with said support member for axially holding the same while a pull force is exerted on said drawbar, means for pulling said drawbar while said support member is held against axial displacement to relieve such thrusting engagement, means for rotating said nut to move it axially along said threaded section away from said support member and thereby loosening it, and means for pushing said drawbar in a direction opposite from the direction in which said drawbar is pulled.
 2. In a machine tool including a tubular spindle having an internally tapered recess for seating the externally tapered spindle-insertable end portion of a tool holder, the improvement which comprises a drawbar arranged in said spindle, the end face of said insertable end portion having a hook recess the mouth of which is formed by an inturned annular lip to provide a tool hook, holder-to-drawbar connection means for releasably connecting said drawbar to said holder responsive solely to longitudinal movement of said drawbar relative to said spindle and including a slide member and a plurality of circumferentially spaced fingers projecting axially from said slide member, the free end of each of said fingers being radially movable and formed to provide an external hook, all such external hooks collectively providing a spindle hook which is radially expandable and retractable, and cam means for moving said fingers radially in and out, said spindle hook when contracted being insertable through said mouth into said hook rEcess past said lip by axial movement of said slide member in a direction toward said end portion and when in such relative axial position being expandable into locked engagement with said lip, and drawbar-movement-control means for moving said drawbar solely longitudinally relative to said spindle, the free ends of said fingers being radially contractile, and said cam means including cam surfaces severally on the radially inner sides of said fingers at said free ends thereof and a cam mounted on said spindle within the cluster of said fingers and engageable with said cam surfaces.
 3. The combination according to claim 2 wherein said cam means further include a sleeve mounted on said spindle and radial struts severally extending in the spaces between adjacent pairs of fingers, said struts at their outer radial ends being connected to said sleeve and at their inner radial ends being connected to said cam.
 4. The combination according to claim 3,further comprising a tool ejector member slidably mounted on said sleeve and having slots receiving said struts and pushed against said end portion by said slide member when axially moved in said direction.
 5. The combination according to claim 3, further comprising a guide spider on said cam adjacent said fingers and including a plurality of radial fins arranged in said spaces having outer guide surfaces collectively having a diameter which is slightly less than the diameter of said mouth. 